#include<stdio.h>
#include<math.h>
int main(){
	int a,b,c;
	float s,area,perimeter ;
scanf("%d %d %d",&a,&b,&c);
s=(a+b+c)*0.5;
area=s*(s-a)*(s-b)*(s-c);
perimeter=s*2;	
area=sqrt(area);
	if(a+b>=c&&a+c>b&&b+c>a){
printf("area=%.2f;perimeter=%.2f",&area,&s);
}
else if(a+b<=c||a+c<=b||b+c<=a)
{printf("These sides do not correspond to a valid triangle");}
return 0;
}
